Aircraft

Sikorsky has received a $3 billion contract to develop the CH-53K shipborne heavylift helicopter – a growth version of the CH-53E – for the US Marine Corps. First flight is scheduled for 2011, with service entry planned for 2015. The USMC plans to buy 156 new-build CH-53Ks to replace its CH-53Es.

The CH-53K has virtually the same deck footprint as the E, but maximum take-off weight rises to 38,420kg (84,700lb), from 33,110kg, and payload/range nearly doubles to 12,250kg over 240km (110nm) in hot-and-high conditions. The cabin is 0.3m (12in) wider, to accommodate an HMMWV internally, but large fuel-carrying composite sponsons cut overall width by 1.83m.

The new main rotor has a low-maintenance elastomeric hub and composite blades with new aerofoil and anhedral tips, and is powered via a new drive system by three 6,000shp (4,500kW)-class turboshafts. Selection of suppliers for the engines, integrated glass cockpit, fly-by-wire flight controls and other systems will be made later this year. Electrical and hydraulic systems will be improved and survivability increased.

The USMC says its 150 CH-53Es will begin reaching the end of their 6,120h fatigue life in 2011 at a rate of up to 15 aircraft a year. Deliveries of production CH-53Ks are to begin in 2013 and be completed in 2022.

• Full-rate production of the US Navy’s MH-60R Seahawk anti-submarine/surface attack helicopter has been approved. Lockheed Martin is prime contractor, with Sikorsky building the helicopter.

GRAHAM WARWICK / WASHINGTON DC